Patent GB-807830-A (GB)
Title: Improvements in machines for cutting strip material, particularly glass
IPC: C03B33/037
Filed: 1956-09-13
Abstract: 807,830. Glass manufacture. PITTSBURGH PLATE GLASS CO. Sept. 13, 1956 [Nov. 14, 1955]; No. 27997/56. Class 56. A machine for cutting lengths from a continuously advancing strip, e.g., of glass leaving the annealing leer, includes a wheel, which is mounted to ride against and to be rotated by the moving glass strip, and cam means responsive to the wheel for initiating the transverse cutting stroke of the cutter. In Fig. 1, the glass strip G is moving from right to left in known manner on rollers 11, the cutting mechanism 17 being of conventional construction comprising a carriage 21 which straddles the strip G and is moved back and forth on guide rails 19. The cutter 25 is traversed across the strip G, on the carriage 21. The carriage 21 is moved from left to right by the engagement of a magnetic clutch 37 and from right to left by engagement of the magnetic clutch 39, the main drive being by a chain 51. The carriage abuts against a switch 61 which is tripped to energise momentarily the coil 64 of a time-delay relay, the contact 65 being thereby closed and kept closed long enough to maintain the energiseation of the magnetic clutch 37 whilst the carriage 21 is moved back to its right hand position. The clutch is energized by a coil 66 which closes contacts 67 when it is energized by the closing of the contact 65. A measuring wheel 91 journalled at 97 on a counter-balanced yoke 100 pivoted at 101, rides upon and is rotated by the glass sheet G. Cams 107, 109 are arranged at different radii on the face of the wheel 91, the cam 107 tripping a switch 83 to energise a solenoid 81 controlling valve means 79 admitting air pressure.to a cylinder 77. The bar 73 is thus raised against the glass on the line previously scored by the cutter 25, the required length being thus snapped off. The cam 109 momentarily closes the switch 111 which energizes a time-delay relay coil 118 to close the contacts 119, 121 and thus energize the clutch 39 for the right to left movement of the carriage 21. The closing of the switch 111 closes a contact to start the motor for moving the cutter 25 transversely across the glass G, the motor being kept running by a holding circuit until the cutter-means reaches a limit switch. The next cutting stroke is in the reverse direction, this again being initiated by the tripping of the switch 111, a reverse winding of the motor coming into operation. Lightening holes 95 may be made in the wheel 91. In the above construction, the cut lengths are always equal to the circumference of the wheel, but, in a modification, the cut-off pieces may be alternately long and short, and the difference in the lengths may be regulated. The measuring wheel is connected to a disc by a chain drive so that the disc rotates once for every two turns of the wheel. The face of the disc is provided with a number, e.g. ten, cams, all adjustable angularly in slots in the disc and all being at different radial distances so that the switches 83, 111 may be positioned to be actuated by one only of the cams. The cams are spaced angularly around the disc over a total angle of about 90 degrees, and diametrically opposed to the cam of greatest radial distance is a cam fixed to the disc and intended to trip the switches 83, 111 irrespective of the positions of adjustment of these switches. The length of the movement of the carriage 21 from left to right is thus determined by the selection of one of the ten cams, and whereas the combined length of two successive cut pieces remains constant, this combined length may be divided into two equal parts of, say 143 inches, at one extreme to two lengths of 212 and 74 inches at the other extreme.